The overall goal of Religious Rush Orders Study Core is to provide detailed accurate longitudinal clinical, neuropsychological and neuropathologic data for persons without dementia, and for comparable persons with mild cognitive impairment and Alzheimer's disease to facilitate externally funded studies of aging and Alzheimer's disease, especially those requiring subject with no or mild cognitive impairment. There are three operational components to the proposed Core. 1) Detailed baseline clinical evaluation on men and women members of religious orders without overt dementia who are over the age of 65, understand the nature of the Core, and sign a brain donation form to document cognitive abilities at entry. 2) Detailed annual follow-up evaluation, identical to the baseline, to document change in cognitive function and clinical status proximate to death. 3) In conjunction with the Neuropathology Core, establish a mechanism to achieve high rates of brain autopsies, document the neuropathologic indices of Alzheimer's disease, and preserve the tissue in a fashion that retains maximum flexibility for use in a variety of experimental procedures. To accomplish these goals, the Core will build on its progress during the first funding period. From January 8, 1994 through August 15, 1995, uniform structured evaluations were performed on 176 Priests or Brothers, and 307 Nuns from Religious Orders in Chicago and five other cities across the country. Contacts have been made to enroll the additional 16? to meet the targeted panel size of 650. Of 315 eligible for their first year follow-up, 306 (97.1 %) have been evaluated. Twenty participants have died, 19 of whom underwent brain autopsy. Preliminary results based on cross-sectional analyses of a small number of persons occupying a narrow clinical spectrum from normality to mild cognitive impairment to very mild disease suggests that the proposed Core can provide a unique resource for definitive studies in this area.